Greetings from Bridging Solutions!

With Hurricane Irma now behind us, we hope to find everyone well as we slowly return to business as usual. This installment of “A Bridge Moment” summarizes the inspection process for emergency flood monitoring of bridges. A flood event caused by a hurricane can compromise the structural integrity of a bridge. Municipalities and private bridge owners should have an action plan in place to assess their bridge inventory and to protect the public safety in the event their bridge is overtopped during a major storm. A bridge inspector will visually inspect the bridge, stream and approach roadway with special attention to the following:

• Horizontal and vertical discontinuity between bridge spans
• Widening or closing of the bridge joints
• Tilt of the abutments and piers
• Vibration or swaying of the bridge from stream flow
• Noises, such as creaks, groans and scraping of the bridge
• The freeboard is measured (i.e. distance from water surface to underside of bridge). If the water is above the bottom of the superstructure, the bridge should be closed immediately.
• Erosion or settlement of the approaching roadways
• Debris flow hitting or snagging the bridge
• Strength and direction of current
• Scour (e.g. degradation of the stream bed). Obtain stream bed elevations and compare to past readings from previous inspections. Underwater diving inspections can be performed if warranted.

With a proper plan of action in place the bridge owner will have the tools necessary to effectively coordinate bridge closures if warranted. Bridging Solutions is qualified to perform emergency flood inspections and also provides flood emergency training seminars for municipal and private bridge owners.